The hypothesis of this study is that genetically corrected peripheral blood stem cells (PBSC) will result in a sustained reversal of the phenotype in patients with Gaucher disease. The specific aims to be achieved are: Transfer of the human GC gene into PBSC obtained from patients with Gaucher disease; Transplantation of transduced PBSC autologously to patients; Measurement of carriage and expression of the transferred gene and its duration in peripheral blood leukocytes (PBL); Assessment of the clinical effects of transplanting genetically corrected PBSC in patients with Gaucher disease.